FUNCTION ICONV(STRING,IVAL)
CC
C	ICONV - CONVERT STRING TO NUMERIC VALUE.
C	ENTRY -
C		-STRING- = STRING TO CONVERT
C
C	EXIT -
C		-IVAL-	= VALUE OF STRING (IF VALUE WAS COMPUTED)
C
	LOGICAL*1   SFC(4), SDEL(3), STRING(1)
	DATA SFC/'"','''','%',0/		!   SPECIAL FIRST CHARS
	DATA SDEL/2,1,3/		!   COUNT FOR TERMINATOR SCAN DELAY
C
	ICONV = 0			!   INITIALIZE FOR NO GOOD
	IACC = 0			!   PRESET NUMBER ACCUMULATOR
	ICH = STRING(1)			!   GET FIRST CHAR OF ENTRY
	ISLEN = LEN(STRING)		!   SAVE CHAR COUNT OF STRING
	ITYP = INDEX(SFC,ICH)		!   CONSTANT TYPE
	IF (ITYP.GT.0)   GOTO 500	!   IF SPECIAL FIRST CHAR
	IF ((ICH.LT."60).OR.(ICH.GT."72))   RETURN	!   IF NOT DIGIT
	IBASE = 8			!   PRESET FOR OCTAL
	IF (STRING(ISLEN).NE."56)   GOTO 100	!   IF LOOKS LIKE OCTAL
	IBASE = 10
	ISLEN = ISLEN-1			!   DONT SCAN THE .
CC
C	HANDLE STRAIGHT OCTAL/DECIMAL CONSTANTS.
C
100	DO 150 I=1,ISLEN
	IDIG = STRING(I)-"60		!   GET NEXT DIGIT VALUE
	IF ((IDIG.LT.0).OR.(IDIG.GE.IBASE))   GOTO 800	!   ILLEGAL DIGIT
150	IACC = IACC*IBASE+IDIG		!   COMPILE VALUE
199	ICONV = -1			!   FLAG EVERYTHING WORKED
	IVAL = IACC			!   TRANSMIT VALUE TO CALLER
	RETURN
CC
C	HANDLE SPECIAL CONSTANTS.
C
500	DO 550 I=2,1+SDEL(ITYP)		!   FOR ALL BUT FIRST CHAR
	IDIG = STRING(I)
	GOTO (510,510,530), ITYP	!   PROCESS PROPER STUFF
510	IACC = ISHFT(IACC,8)+IDIG	!   PUT IN NEXT DIGIT
	GOTO 550
530	IDIG = INDEX(' ABCDEFGHIJKLMNOPQRSTUVWXYZ$. 0123456789'
	1	,IDIG)	!   CHECK IF LEGAL RAD50
	IF (IDIG.LE.0)   GOTO 800	!   IF NOT LEGAL RAD50
	IACC = IACC*"50+IDIG-1
550	CONTINUE
	GOTO 199			!   EXIT HAPPILY
CC
C	GENERAL EXIT TO FLAG ILLEGAL DIGIT
C
800	ICONV = 1
	RETURN
	END